Glock 21SF Gen4 slim-frame .45 ACP combining the SF grip reduction with Gen4 improvements including the modular backstrap and RTF4 texture. Type: Pistol Action: Semi-Automatic Caliber: .45 ACP Capacity: 13 Year introduced: 2013, Austria Weight: 26.28 oz Overall length: 7.59" Status: Active Intended use: Service, Duty, Home Defense